I. Field of the Invention
The present invention relates to a cryogenic storage container system.
II. Description of Related Art
There are many previously known cryogenic storage container systems for storing biological specimens, e.g. sperm, blood, embryos, etc., at low temperatures, e.g. −190° C. Many of these previously known cryogenic storage containers include a cylindrical tank defining an interior in which the specimens are contained. The tank is then cooled with liquid nitrogen in order to maintain the cryogenic temperatures within the interior of the tank.
The biological specimens are typically contained within small straws which, in turn, are positioned within a storage unit container (SUC). These SUCs are typically rectangular in cross-sectional shape and dimensioned and sized to hold a plurality of biological specimens.
In order to maximize the number of biological specimens that may be contained within a single cryogenic tank, many previously known cryogenic storage containers have included a plurality of turntables which are independently rotatably mounted to each other and positioned within the interior of the tank so that the turntables are positioned one on top of each other. Each turntable, except the lowermost turntable, includes a cutout or removed section to provide access to the turntables beneath that turntable layer.
Each turntable, furthermore, includes a plurality of compartments wherein each compartment is dimensioned to receive one SUC. Consequently, by rotating the turntables relative to each other, access to any particular compartment, and thus any desired biological specimen within the interior of the cryogenic tank, may be achieved.
One previously known disadvantage of these previously known cryogenic tanks, however, is that in order to retrieve a particular SUC containing a desired biological specimen or specimens, it was necessary to move the SUC into a position above the uppermost turntable and thus, into the relative warm zone of the cryogenic tank. In some cases, this movement of the SUC caused a thawing and thus destruction of the biological specimen.
A still further disadvantage of these previously known cryogenic storage containers is that, in order to obtain and SUC from one of the lower turntables, it was necessary to snag the SUC using a hook or similar device. Such hooks, however, are time consuming and difficult to use. Furthermore, in the event that the SUC is not firmly engaged by the hook, the SUC can disengage from the hook and be damaged.